In known systems, when a radiological medical image is electronically processed or analyzed, the static background can overwhelm and obscure information of interest. Removing static background substantially enhances the visibility and therefore the automatic detection of moving or changing anatomical features. Removing static background detail also improves image visualization by eliminating the clutter of inconsequential detail of the background. A known method for background removal involves Digital Subtracted Angiography (DSA). DSA is mainly used for visualization of blood vessels filled with a contrast agent (e.g., an X-ray opaque dye). DSA involves acquiring a reference image (called a mask) which contains only background detail. For angiography a mask comprises an image acquired before injection of a contrast agent into patient anatomy. In known systems, in order to remove static background detail from images, a mask image is subtracted from subsequent images acquired when a contrast agent is in the blood which yields a clear picture of blood vessels filled with the contrast agent.
DSA cannot be performed if a background mask image is unobtainable such as if it is required to enhance an image of a catheter placed in a patient heart. Even if the catheter could be removed to acquire a background image, patient movement (including respiratory and heart beat movement) impairs a mask image. A system according to invention principles addresses these deficiencies and related problems.